Filter and capping head



Jan.24, D,S.D0PP ETAL I 3,299,507

FILTER AND CAPPING HEAD Filed Dec. 5,1963 4 Sheets-5heet 1 INVENTORS DAVID 5. DOPP PETER R.-MUCIBABICH Jan- 2 5 D. s.- DOPP ETAL FILTER AND CAPPING HEAD 4 Sheets-sheet 2 Filed Dc. s. 1963 DAVID S. DO'PP PETER F2. MUCIBABICH Quit?? Jan. 24, 1967 s. DOPP ETAL 3,299,607

' FILTER AND CAPPING HEAD Filed Dec. s, 1963 4 Sheets-Sheet 5 INVENTORS DAVID S. DOPP PETER R. MUCIBABICH United States Patent 3,299,607 lFllLTER AND CAPPING HEAD David S. Dopp, Chicago, and Peter R. Mucibabich, Schiller Park, Ill., assignors to Continental Can Company, Inc, New York, N.Y., a corporation of New York Filed Dec. 3, 1963, Ser. No. 327,620 18 Claims. (Cl. 53-87) This invention relates to anew and improved means for use in container vacuum capping, and more specifically, is directed to a new and improved filter and capping head of uncomplicated design which is particularly adapted for capping containers filled with particulate or powdery material, the retention of which is difficult to control during normal container evacuation and capping operations.

A wide variety of proposed types of vacuum capping machines have been presented to the art, some of which are capable of eificient use. In general, such machines are oftentimes quite complicated with regard to structural and operational aspects, and are difficult to maintain in eflicient operating condition. The particular problems arise when the vacuum sealing machines of known prior art types are to be used in vacuum packing. operations for a diverse variety of products. Notable among these products is instant coffee, and like products, which may be categorized as powdery, particulate material types. These create vacuum packaging difiiculties due to their tendency to be readily displaced from the container when subjected to the vacuumization process condition.

Several solutions have been proposed to obviate this problem by employing a filter means such as a cloth or screen over the mouth portion of the container during the evacuation process. As a general rule, residual oxygen content ideally should not exceed more than two percent and in most instances, should be less. Therefore it is necessary to draw a very high vacuum in order to obtain this low oxygen condition within the container prior to capping off thereof. The use of such high vacuums has caused the finely ground particulate material to be drawn against the filter means in existing prototypes, resulting in the interstices becoming clogged with the particles of the product which was obviously undesirable.

A specially designed high speed vacuum capping machine particularly adapted for efiicient use in capping containers filled with particulate material such as instant coffee is disclosed and claimed in the copending applications Ser. No. 122,498, filed July 7, 1961 and Ser. No. 122,973, filed July 10, 1961, now Patent Nos. 3,191,354 and 3,220,152. These applications disclose machines capable of vacuum treating a container filled with particulate or powdery material to provide for a residual oxygen content of at least as low as two percent oxygen on the basis of the free volume of the container.

The capping speed, which is about three hundred containers per minute, and the evacuation efficiency of these machines constitutes a material advance in the art when contrasted with prior developments. In this respect, prior art machines may be able to match the speed of opera tion, however fail to evacuate the containers to the desired level, or vice versa.

The present invention deals with a unique container evacuation filter and capping head for use in the machines mentioned above the like devices, with the present invention materially contributing to the efficiency of the operation thereof as well as permitting, along with complementary structure, a rapid changeover from one size of container to another. In the present device, the simplified construction of the filter and capping head maximizes i the available area of filter surface for expeditious and relatively thorough evacuation of the container. In addition, the provision of a new and improved cap gripping means of uncomplicated construction, permits the full surface of' the filter to be available to promote increased efiiciency in back flushing or reverse flow, which also con-' tributes to the reduction in the overall time of the operation. Suitable means is provided in conjunction with the cap gripping means for effecting a controlled grip of the cap, with suitable adjustments provided for fine gripping control and also to compensate for wear. Additional means is provided to prepare the cap gripping means for reception of a cap, which means also ejects an unused cap therefrom should no container be presented for capping off. This reduces the possibilities of the machine becoming jammed which obviously would interfere with the high speed operation thereof. The numerous advantages and benefits of the present invention will become apparent upon an examination of the objects to be accomplished and a full description of the device as set forth below.

It is therefore an object of the present invention to provide a new and improved filter and capping head for use in a vacuum capping machine during evacuation of a filled container and cap application thereto.

Another object of this invention is to provide a vacuum capping machine having a special filter and capping head adapted for efficient and positive operation during the evacuation and capping application of a container, the filter portion of the unit being of a particular design to maximize the evacuating area and being especially capable of preventing excessive displacement of the powdery product from the container during evacuation thereof.

It is a further object of this invention to provide a new and improved filter and capping head having a cap gripping means associated therewith including means to selectively constrict the same for force controlled gripping engagement thereof.

It is a still further object of this invention to provide a new and improved filter and capping head assembly wherein the path between the mouth of the container and the filter is devoid of obstructions thereby to avoid the deposition of the particulate material thereon or adherence thereto.

It is a still further object of the present invention to provide a filter and capping head having means associated therewith to cock the cap clamping mechanism on each cycle and further serving to eject the cap therefrom in the event no container is presented for capping off.

It is a still further object of this invention to provide a cartridge type container gripping means which is easily replaced by one of a different size, along with expeditiously facilitating a complementary change in the filter capping head to accommodate the appropriate cap size.

Further and fuller objects other than those specifically set forth will become apparent from the following detailed description of the invention made in conjunction with the accompanying drawings wherein like reference characters indicate like parts.

FIG. 1 is an enlarged fragmentary, partial vertical section of one of the vacuum chamber and cap application assemblies of the evacuating and capping machine, illustrating the filter and capping head of the present invention as well as the other structure adapting the machine for operation in accordance with the principles enumerated above;

FIG. 2 is an enlarged bottom plan view of the filter and capping head of the present invention taken along the lines 2-2 of FIG. 1;

FIG. 3 is a fragmentary enlarged half section of the filter and capping head of FIG. 1 with a fragmentary portion of the container cap in the gripped position;

FiG. 4 is a view similar to FIG. 3 with the clamping lugs moved to the unlocked position;

FIG. 5 is a top free body plan View of the lower ring forming a part of the filter and capping head assembly;

FIG. 6 is an enlarged perspective view of the filter used in the filter and capping head assembly of the present invention;

FTG. 7 is a partial view similar to FIG. 1 illustrating the operational aspects of the assembly during the evacuvation of a container;

FIG. 8 is a fragmentary view similar to FIG. 7 illustrating additional operational aspects of the filter and capping head assembly;

FIG. 9 is a fragmentary view similar to FIG. 8 with the filter and capping head in the raised and unlocked position to receive a cap member from a cap delivery device;

FIG. 10 is a view similar to FIG. 9 showing the filter and capping head in cap receiving engagement with the cap member;

FIG. 11 is a fragmentary view similar to FIG. 10 with the cap delivery device backed off and the filter and capping head holding the cap member for application to a container; and

FIG. 12 is a view similar to FIGS. 7-11 illustrating the cap being applied to a container.

The vacuum capping machine of FIG. 1 is fully disclosed in the aforementioned copending applications and will be briefly described herein insofar as necessary to understand the co-operative relationship of the filter capping head and container gripping means therewith. As best shown in FIG. 1, reference character 10 indicates a fragmentary portion of an evacuating and capping machine. The machine 19 includes a plurality of vacuum chamber and cap application assemblies one of which is indicated generally at 11, which are mounted on a rotary turret, as defined in the aforementioned copending applications. Each of the vacuum chamber and cap application assemblies 11 generally includes a bell shaped housing 12 forming a container receiving chamber 13, a valve assembly 17, and a cap delivery assembly 18. A movable platen as sembly 14 carries a container 15 and co-operates with the housing 12 to close the container receiving chamber 13.

The complete cycle of operation of the machine, a fragmentary portion of which is indicated at 10, is adequately described in the aforementioned copending applications and briefly includes feeding filled containers to the machine wherein they are automatically placed on a lowered platen member carried by the container supporting assembly 14 as illustrated in FIG. 1. As the container moves on the platen in a circular path, it is raised by the platen to confine it within the container receiving chamber 13, while the chamber is evacuated and inert gas back fed into the same. The evacuation and inert gas back feeding cycle may be repeated and subsequently, the cap is applied in complete sealing engagement. Operations continue until the container is ready for delivery to the packing conveyor as will be described.

The container receiving chamber 13 formed in the bell housing 12 is provided at its bottom open end with a container gripping assembly 19 which is received in gastight engagement (by means of an interposed O-ring) within the bell housing 12. The assembly 19 includes a continuous slot 20 in which is mounted a resilient container gripping member 21, having an outer circumferential portion of generally outwardly open channel-like shape. The container gripping member 21 is received in gastight engagement at its upper and lower end portions within the slot 20 which is formed in a container gripping housing 22. The channel shaped outer circumferential portion of the gripping member 21 is in communication with the atmosphere through a plurality of radially extending openings or fluid ports such as the one shown at 23. Under some conditions, particularly when the containers are to be filled with an inert gas instead of being vacuumized it is necessary to connect the fluid ports 23 to a source of air at :a super atmospheric pressure. In such a case a suitable automatically operated valve (not shown) is necessary to selectively control the supply of air to the fluid ports 23 and the venting of the fluid ports to the atmosphere.

The lower end of the container gripping housing 22 is trimmed by a generally L-shaped member 24 which is removably aifixed to the housing 22 and carries at its lower extremity a platen engaging gasket 25. The container gripping member 21 is formed to define a series of slots 26 between each of a plurality of spaced rib-like members 27 to permit the free constriction of the container gripping member under the influence of atmospheric pressure, or super atmospheric pressure, whereby it will be moved into engagement with the outer periphery of the container 15. The container gripping assembly 19 is in the form of a cartridge removably received in the housing'12 in order to effect any necessary repairs as well as permitting expedient changing thereof to accommodate different sizes of containers.

The valve assembly 17 includes a valve housing 28 which is mounted on the housing 12 in association with an open side manifold portion 29 of the housing 12 which is in communication with the chamber 13. Three valve chambers 38, 31 and 32 are included in the valve assembly 17, with the outer end of each defining valve seats in the manifold area 29. Poppet valves 33, 34 and 35 close off the respective valve chambers and are operated on rods which carry at their opposite ends cam rollers (not shown) for sequentially actuating the same in timed relation to the evacuating and capping cycle. Any suitable spring arrangement (not shown) may be used in maintaining the valves in chamber sealing engagement with the associated seat. Chamber 30 is provided with a passage 30' which is in communication with an inert gas supply. Chamber 31 is in communication with the atmosphere through a suitable vent (not shown), and chamher 32 communicates through passage 36 with the pipe 37 leading to a suitable source of vacuum.

Each vacuum chamber and cap applicator assembly 11 includes a cap delivery assembly 18 being illustrated as including a cylindrical housing 38 open at one end and mounting a continuous gasket 39, while the other end of the housing 38 is journaled in sealed relationship on the rod-like member 40 for relative movement with respect thereto. The rod it? at its inner end mounts a cap supporting boss 41 on which a cap 42 may be deposited by means of a suitable feed. The container cover or cap 42 applied to the container 13 is of the rotatable type having a fiat top panel portion formed with a depending skirt portion along the inner surface of which locking lug type means are provided for engagement with the outer surface threaded ortions of the neck or rim of the container in a manner well known in the art. The housing 38 is slidable along the rod 40 toward and away from the chamber 12 by means of supporting rods 43 (only one of which is shown) these rods being suitable reciprocably journaled in a portion of the housing 12, with the rod 43 illustrated extending inwardly beyond the housing 12 and carrying thereon an actuation means more completely described in the previously mentioned copending applications.

A filter and capping head 16 is removably mounted on the bottom end of a shaft 44 by means of a threaded end portion 45 received in complementary threaded portion 49 in a filter mounting head 46 forming a part of the filter and capping head assembly 16. The filter mounting head 46 is of generally annular configuration having three radially inwardly extending mounting arm portions (only two shown at 47 and 48) which converge to a generally circular central section accommodating the threaded bore 49 to threadably receive the bottom threaded portion 45 of the shaft 44. The mounting arm portions are angularly spaced 2. sufficient distance to allow gas pass-age therebetween to the outer surface of the filter member indicated generally at 50.

The filter 50 is carried within the filter mounting head 46 by means of spaced lugs to be described in conjunction with FIG. 6, and is fixedly held to the filter mounting head 46 so as to be movable therewith. The filter is of rigid porous material being formed in an inverted cuplike shape having an endless side wall portion 51 and a top wall portion 52 joined thereto by means of a smooth arcuate section. The lower end of the filter member 50 has a ring 53 of trapezoidal cross section attached thereto. The lower radial surface of the ring 53' mounts a sealing gasket 54 of soft elastomeric material for sealing engagement with the upper rim portion of the container 15. It is to be appreciated that the annular side wall portion 51 of the filter member 50 is of substantial height, being sufficient to provide a barometric leg effect during the head space evacuation to permit efiicient retention of the particulate material in the container 15. The particular details of the construction of the filter member 50 will be given in conjunction with the description of FIG. 6.

The filter and capping head assembly 16 further includes an upper ring member 55 and a lower ring member 56 joined together in spaced relationship by means of a plurality of longitudinal pin members 57 having end portions attached thereto. The upper ring 55 and lower ring 56 together with the pin members 57 form an assembly 65 which constitutes a trigger and generally encompasses the filter mounting head 46 and is free for longitudinal movement relative to the filter mounting head 46 to effect triggering the release and gripping of a container cap in a manner to be described.

Referring now to FIGS. 2-4 a pair of longitudinally spaced link members 58 and 59 have one end thereof joined to each of the pin members 57 with the other end of each being connected to a clamping member 60. An annular groove 61 is provided in the clamping member 60 between the link connections thereto and receives a clam-ping spring 62 which resiliently joins the clamping member 60 to the filter mounting head 46, The annular groove 61 is in circumferential alignment with a co-operating groove 63 provided in the filter mounting head 46 as seen in the right hand portion of the filter and capping head assembly 16 in FIG. 1 to provide a continuous annular seat for the spring 62.

The link members 58 and 59 are spaced and angularly placed with respect to each other so as to provide a toggle action to the clamping member 60 as the trigger assembly 65 on which they are pivotably mounted is shifted upwardly and downwardly relative to the filter mounting head 46. Throughout this relative movement the clamping spring 62 holds the clamping members 60 against vertical movement relative to the filter mounting head 46 for reasons to become apparent. The filter mounting head 46 is provided with a guide portion 64 slidably received over an upper portion of each guide pin 57 which is of a generally cylindrical configuration.

As seen in FIG. 4, the trigger assembly 65 is in the down or unlocked position relative to. the filter mounting head 46 causing the lower link 59 to be in a generally horizontal position, with the upper link 58 angulated upwardly to draw the upper end of the clamping member 60 radially inward to space the lower end clamping lug portion 66 of the clamping member 60 a slight amount from the container cap gripping ring 67. In FIG. 3 as the container cover member 42 engages the gripping ring 67 of the trigger assembly 65 during descent of the filter and capping head 16, it causes the trigger assembly to be arrested. As the filter mounting head 46 continues moving downwardly a slight amount the relative movement between the trigger assembly and the filter mounting head 46 causes the upper link member 58 to be moved to a generally horizontal position while the lower link 59 is moved to the downwardly angulated position shown.

This serves to pull the clamping lugs 66 of the clamping members 60 toward the periphery of the gripper ring 67. The clamping lug portion 66 of each clamping member 60 is provided with a tapped hole 92 for reception of a set screw 93 having a rounded nose portion 94 for cooperation with a wear pad 95 bonded to the gripping ring 67. This permits ready adjustment of the constricting force on the ring for controlling the gripping force and to compensate for wear.

The gripper ring 67 is formed from elastomeric material into an annular configuration having a radially inwardly projecting flange 68 forming a cap receiving shoulder 69. The cap gripping ring 67 is of harder rubber than the concentrically disposed sealing ring 54. As seen in the plan view of FIG. 2, the shoulder 69 is provided with a plurality of equally spaced upstanding fingers 70 to assist in imparting rotational motion to the cap 42 in the capping operation. This will become apparent hereinafter when the evacuation and capping cycle is explained in conjunction with FIGS. 7-12.

The top plan view of FIG. 5 illustrates the lower ring 56 as being provided with three guide slots 71, 72 and 73 for co-operation with downwardly projecting guide lug portions such as that indicated at 74 on the filter mounting head 46 as best seen in the right-hand portion of FIG. 1. The guide slots 7173 serve to transfer the rotary motion from the shaft 44 and the filter mounting head 46 to the lower ring assembly 56, which in turn mounts the container cap 42 within the gripper ring 67 in the manner previously described. In the absence of the guide slots 7173, rotational motion would be transferred to the lower ring 56 through the pin members 57, possibly causing distortion or bending thereof.

'The lower rectangular ends of the pin members 57 are received in radially directed slots 75, 76 and 77, with a countersunk threaded fastener such as the one indicated in dotted lines at 78 (FIGS. 3 and 4) passing through the lower ring 56 into threaded engagement with the rectangular portion of the pin member 57. An additional series of countersunk portions 79, 80 and 81 are provided on the internal periphery of the ring 56 to accommodate the head portions of fasteners (not shown) which mount the filter member on the filter mounting head 46 in a manner to become apparent.

As seen in FIG. 6 lug portions 82 and 83 on the filter member 50 are angularly spaced an amount equal to spacing between the countersunk portions '80 and 81 in the lower ring. Threaded fasteners passing through the lugs co-operate with a tapped portion in the filter mounting head 46 to draw the lugs into abutment with a lug receiving counter bore in the radial surface indicated by dotted lines at 91 in FIG. 1. The relative position of these is seen in dotted lines in FIG. 2, being in axial alignment with the countersunk portions 79, 80 and 81 on the ring 56. Thus the filter is fixed to and movable with the filter mounting head 46 as well as the clamping member 60.

The filter member 50 may be formed from any suitable rigid material capable of providing the requisite porosity and strength for use in the manner described. For example, the filter member may be formed from sintered metallic particles such as beads or the like having an average particle size from 26 to 51 microns. One specific metal which has been found to be successful is brass beads which are suitably charged in a mold, heated to a temperature of approximately 1,680 F. in the presence of a hydrogen atmosphere. A lower temperature may be used Where a nitrogen atmosphere is present, such being of the order of l,620 F. In either case, such temperatures combine the accumulative mass of beads in the mold cavity in a well known manner to form a sintered article which is uniformly porous throughout.

The filter member may also be formed from sintered nylon powder or other suitable materials. To form such a filter, fine nylon powder on the order of 1 to 3 microns is compacted in a mold at about 15 to 50 tons per square inch pressure and sintered at about 450. A non-oxidizing atmosphere, such as inert gas, vacuum or oil, is provided during the sintered process. Filters formed in this manner and of this type are of the same shape as that shown in FIG. 6 and as previously described, with the pore walls being sufficiently rigid and small to prevent particle entrapment. Irrespective of the manner in which the filter member 50 is made, the inverted cup shape is such that a barometric leg effect is provided. The importance of this is evident, when viewed in light of the operational aspects of the present invention, since as previously described, powdery materials are rather difficult to handle during evacuation of a container filled with the same. The generous height of the side wall portion 51 of the filter member 50' provides a substantial amount of space confined by the filter member in communication with the rim or mouth portion of the container 15. Thus, the evacuation procedure or process is substantially completed before the finely divided or particulate material can rise well above the container rim.

In addition, the lack of any obstructions between the mouth of the container and the top wall portion 52 of the filter permits vacuum conditions to be established virtually instantaneously, promoting an efficient high speed operation of the capping machine. The immediate subjection of a strong vacuum on particulate material has a tendency to lift the same, however, in the present embodiment a barometric leg defined by the filter member 50 is kept within the limits of about 1 /2 to 3 /2 inches. A height of 3 inches has been found quite satisfactory in a capping machine of the type described which .as previously noted will operate at approximately 300 containers per minute. The barometric leg provides an area in which finely divided or particulate materials may expand upwardly, resulting in separation of the particles topermit air to be readily withdrawn at maximum velocity from the container.

The unobstructed path from the container through the rigid porous filter member does not present any surface on which the finely divided or particulate material may cling either due to the charge :on the particles or other modes of attraction of the particles to the surface. In addition, back flushing or reverse flow of the inert gas serves to clean all the interior surface area of the filter. In this regard, the rigid porous member provides greater pore wall strength and constitutes a substantial improvement over the use of silk filter screens or analogous devices.

A more complete understanding of the operational aspects of the filter and capping head in conjunction With the capping machine will be had upon a full description of the operational cycle of the device insofar as the evacuation and capping off is concerned. In FIG. 7, the platen 14 has moved the previously filled container 15 within the container receiving chamber 13. Translation of the rod 43 has shifted the cylindrical housing member 38 with respect to the rod 40 to bring the sealing member 39 into sealed engagement with a side wall portion of the bell housing 12. The platen assembly is also in sealed engagement with the platen engaging gasket 25 to close off the lower portion of the housing 1 2 while the shaft 44 is sealed in any suitable manner to provide a closed gastight evacuation chamber.

The container 15 has the rim or mouth portion engaged by the sealing gasket 54 on the filter capping head 16 and subsequent to the engagement thereof, the poppet valve 35 opens, placing chamber 32 in communication with chamber 13 to evacuate the same. The container 15 is evacuated through the filter 50 in an expeditious manner since a rather substantial area of the side and top wall portions 51 and 52 of the filter member 50 is exposed to the vacuum source. During evacuation of the chamber 13, atmospheric pressure enters through the radial fluid ports 23 to act on the outer peripheral portion of the container gripping member 21. causing the spaced riblike members 27 to constrict into gripping engagement with the outer surface of the container 15, so as to hold.

the same against translation and/or rotation within the chamber 13. The circumferential spacing of the ribs 27 provides for pressure equalization above and below the container gripping member 21 through the longitudinal slots 26. This in turn promotes the establishment of a vacuum condition below the container gripping member 21 to aid in maintaining a tight seal between the platen assembly 14 and the platen engaging gasket 25.

The arrows in the cross sectional view of FIG. 7 indicate the general path of the air as it is evacuated through chamber 13 into chamber 32 and out the pipe member 37 which leads to the vacuum source. The particular level of evacuation. will be described more completely hereinafter, however, in order to appreciate the operational aspects, evacuation to at least 2-5 inches in mercury vacuum is utilized in the first evacuation step. Upon completion of adequate evacuation of the chamber 13 and the container 15, poppet valve 35 is moved to the closed position as a result of cam actuation, and subsequent thereto, poppet valve 33 is opened as illustrated in FIG. 8, placing a supply of inert gas in communication with the chamber 13.

As the inert gas enters the chamber 13 it passes in reverse through the filter member 50 into the head space of the container in the path generally represented by the arrows. This operational step is preferred in that reverse flow through the filter member tends to keep the same clean while also re-depositing any particulate material collected thereon back into the container. The amount of inert gas supplied to the chamber 13 reduces the vacuum to no less than 10 inches of mercury, preferably of the order of about 15 inches.

Upon arrival at the proper level of vacuum, poppet valve 33 is closed and the vacuum control valve 35 is re-opened to reduce the pressure in the chamber 13 and remove the inert gas therefrom. A subsequent control-led feed-back of inert gas will possibly be relied upon for purposes of reducing the vacuum established in the container to facilitate ease in the removal of the cap from acontainer by the user thereof.

Upon completion of the vacuumization and inert gas injection cycles, the filter and capping unit 16 is retracted upwardly by the shaft 44. At this time, the rod 40 of the cap delivery assembly 18 is actuated to move the cap supporting boss 41 into the interior of the chamber 13 stopping in longitudinal alignment with the inner peripheral portion of the gripper ring 67. Throughout this step, the prescribed vacuum conditions are maintained. The filter and capping head 16 is lowered into engagement with the cap 42 as seen in FIG. 10, and as the filter and capping head 16 moves downwardly, the pressure exerted by the cap against the lower ring 56 arrests the downward travel of trigger assembly 65 resulting in a relative upward shifting of the trigger assembly 65 with respect to the filter mounting head 46, as the filter mount-- ing head moves further downwardly to complete its stroke. At this point, the clamping lugs 60 engage the outer circumferential portion of the gripper ring 67 in the manner best seen in the enlarged view of FIG. 3.

A positive grip is thus obtained on the skirt portion of the cap member 42 with the fingers 70 flexed into tight engagement with the outer periphery of the flat top panel portion of the cap 42. With the cap member 42 so engaged, the filter and capping head assembly 16 is drawn upwardly to clear the boss 41 which is withdrawn into the sleeve housing in the manner illustrated in FIG. 11. At this point, the cap is substantially in longitudinal alignment with the rim of the container 15 shown frag-- mentarily in FIG. 11. The chamber 13 is maintained at the properly evacuated level as the filter and capping head assembly 16 is moved downwardly towards the rim of the container 15.

As best seen in FIG. 12, the gripper ring 21 holds the container 15 fixed with respect to the gripper housing 22.

The shaft 44 is rotated causing the filter and capping head assembly to rotate imparting rotation to the cap member through the guide lugs 74 being interengaged with the guide slots 71-73 in the lower ring 56. Rotation-of the shaft 44 serves to twist the cap 42 onto the container 15 in hermetic sealed relation. The fingers 70 grip the outer peripheral portion of the fiattop panel of the cap 42-to impart rotary motion to the cap 42. As the shaft 44 is subsequently raised, the gripping force-of the gripper ring'21 on the container 15 is greater than the gripping force of the gripper ring 67 engaging the cap 42 and the same is withdrawn from the gripper ring 67. However, prior to release, in order to effect proper hermetic sealing, the top edge of the container 15 is embedded in a gasket material carried within the cap 42. Thus, it is to be appreciated that the downward pressure of the filter and capping head 16 is rather substantial and throughout this operation, a special locking means (not shown holds the platen assembly 14 from shifting downwardly which would serve to break the vacuum.

As the filter and capping head 16 is moved upwardly to the position shown in FIG. 1, the upper ring 55 of the trigger assembly 65 engages a stop member 90 preventing further upward movement thereof. As the shaft 44 continues its-translation, the'filter mounting head 46 is pulled upwardlymoving relativeto the'upper and lower ring 55 and 56 of the trigger assembly 65 thereby triggering or cocking the clamping members 60 to the condition more clearly seen in the enlarged view of FIG. 4. The cycle may then. be repeated. In addition to cocking the trigger assembly 65 and clamping members 60 of the filter and capping head 16 to prepare for the next cycle, the unique stop means cooperating with the filter and capping headserves to eject a cap member in the event a container was not presented for capping off. This serves to insurethe continuous function of the machine preventing the same from becoming jammed or the like. Throughout the high speed capping operation it has been found that a vacuum of the order of 26 /2 inches of mercury may be quickly established (approximately 0.2 second) in a closed chamber such as the one indicated at 13. Vacuums of. higher order such as 28 /2 inches of mercury are difficult to establish, as well as acquiring a longer period of time due to the air molecules remaining widely dispersed. As pointed out previously, in order to accommodate the wide variety of oxygen sensitive food products, the container should be preferably evacuated to an extent that the residual oxygen is not substantially greater than 2 percent. This would require the establishment of a vacuum of the order of at least 28 inches, and increase the time required.

It has been found that" the useof a series of evacuations interspersed with inert gas feed-back will assist in expeditiously bringing the desired residual oxygen content to the desired level while maintaining high speed capping operation. Initially, the'vacuumization cycle establishes about 25 inches of mercury vacuum. This vacuum is then reduced by the injection of an inert gas, such as nitrogen, decreasing the vacuum (to no less than inches of mercuryvacuum. A dilfusion of the :air within the chamber results from the feed-back of nitrogen presenting a new gas mixture of lower percent oxygen for a subsequent vacuumization. The subsequent evacuation process becomes more effective with regard to the percent of oxygen when contrasted with the first evacuation cycle. In this regard, the barometric leg portion of the filter member 50 contributes substantially as it provides an increase nitrogen fill volume to assure good mixing of the residual air and oxygen. Upon evacuating to at least about 25 inches of mercury vacuum the nitrogen mixed with the residual air is removed from the container resulting in a material reduction in residual oxygen content. The chamber is then reduced to 26/: inches of vacuum and subsequently relieved by the introduction of the inert gas to about inches of vacuum and no less than 10 10 inches. At this point the cap is applied in the manner heretofore described. The sequence of steps can be repeated to any extent desired depending upon the desired level of oxygen content.

Obviously, certain modifications and variations of the invention as hereinbefore set forth may be made without departing from the spirit and scope thereof. As an example, the invention can be used to apply press on type caps as Well as the twist on type described. In applying press on type caps the machine is modified so as to prevent the turning of the shaft 44 and hence the filter and capping head 16 during capping operations. Therefore only such limitations should be imposed as are indicated in the appended claims.

We claim:

1. In a vacuum capping machine wherein containers filled with particulate material are subjected to evacuation and subsequent capping, the provision of a combination filter and cap application unit adapted to cover a container during evacuatin thereof to prevent displacement of said material therefrom and thereafter apply a cap to said container to seal the same, said filter and cap application unit comprising an inverted cup-like filter member resenting an uninterrupted porous filtering area throughout, filter mounting means supporting said filter member in unobstructing relation throughout at least substantially the entire filtering area thereof, cap gripping means at least partially carried by said filter mounting means and associated with the bottom marginal area of said filter member to engage a cap across a mouth portion of said filter member, and means mounting said filter and cap application unit for reciprocation into and out of association with a container for container evacuation and cap transfer.

2. The vacuum capping machine of claim 1 wherein said cap gripping means includes depending radially movable means arranged to engage a cap along the outer periphery thereof, and operating means for said movable means actuated during reciprocation of said filter and cap application unit.

3. The vacuum capping machine of claim 1 wherein said cap gripping means on said filter and cap application unit includes an annular elastomeric ring like member having an axially facing L shape groove portion, and means acting on a peripheral portion of said ring like member to constrict a portion thereof into gripping relationship with a cap.

4. The vacuum capping machine of claim 1 wherein a soft sealing gasket is mounted around the mouth portion of said filter for sealing engagement thereof with a container rim.

5. In a vacuum capping machine wherein containers filled with particulate material are subjected to evacuation and subsequent capping, a filter and cap application unit for filtering fluid during evacuation of said container and subsequently applying a cap thereto comprising, a fi-lterm-ount'ing head, a trigger assembly mounted for reciprocal movement relative to and encompassing said filter mounting head, a container cap gripper ring carried by said trigger assembly and clamping means co-operat ing with said container cap gripper ring to constrict a peripheral portion thereof into gripping engagement with a container ca said clamping means being movable into and out of engagement with said container cap gripper ring in response to reciprocating movement of said trigger assembly with respect to said filter mounting head.

6. The device of claim 5 wherein an inverted cup shaped filter formed from rigid porous material is carried by said filter mounting head, said cup shaped filter having the unobstructed open end thereof facing in the direction of a lower end of said trigger assembly.

7. The device of claim 6 wherein a soft annular gasket is mounted around a lower rim portion of said inverted cup shaped filter.

8. The device of claim wherein said clamping means co-operating with said container cap gripper ring comprises a plurality of axially extending clamping members each having a clamping lug portion thereof extending below said filter mounting head, said clamping members being pivotably carried by said trigger assembly for radial shifting relative thereto, and means interconnecting said clamping members and said filter mounting head for moving said clamping members and particularly said clamping lug portions thereto and radially to selectively constrict said gripper ring with a predetermined force for gripping engagement with a container cap.

9. A filter and cap application unit for use with a vacuum capping machine comprising a trigger assembly having a central bore therethrough, filter means formed from sintered particles positioned in said bore, said filter means having an endless side wall portion subtsantially conforming to the shape of said bore and being closed at one end by a top wall portion to form an unobstructed generally cup shaped filter member substantially filling said central bore, a container cap gripper ring at one end of said trigger assembly for gripping a container cap, and said means mounted on said trigger assembly for axial shifting relative thereto to constrict said container cap gripper ring after said container cap has been received therein.

10. The filter and cap application unit of claim 9 wherein said filter means is provided with seal means around a bottom portion of said side wall portion thereof, said seal means being adapted to engage a rim portion of a container to provide for evacuation solely through said filter means.

11. In a vacuum capping machine wherein containers filled with particulate material are subjected to evacuation and subsequent capping, the provision of a filter and capping head adapted to cover the opening of a container during evacuation thereof and thereafter apply a container cap to said container in a hermetically sealed man ner, said filter and capping head including upper and lower mounting rings, means holding said rings in axially spaced relation to define a shiftable trigger assembly, a container cap gripper ring mounted on said lower ring for gripping engagement with a container cap, an annular filter mounting head encompassed by and carried between said upper and lower rings and having an inverted cup shaped filter mounted therein for movement therewith, seal means on a lower portion of said cup shaped filter for sealing engagement with a container rim, clamping members pivotably mounted on said shiftable trigger assembly and having clamping lug portions thereof overlying a peripheral portion of said container cap gripper ring, and means interconnecting said clamping members and said filter mounting head to move said clamping member clamping lug portions radially inwardly into constricting engagement with said container cap gripper ring to hold a container cap therein.

12. The device of claim 11 wherein said means holding said rings in axially spaced relation comprises pin members and the clamping members are mounted on said pin members by means of a pair of :link members having an end portion thereof pivotably fastened to each of said members.

13. The device of claim 12 wherein said container cap gripping ring is provided with a plurality of axially extending fingers to impart rotation to said container cap, and guide lug means extends from said filter mounting head into co-operating guide slots in said lower ring.

14. The device of claim 13 wherein said filter mounting head is provided with a threaded portion for quick attachment to a reciprocab-le and rotatable shaft member.

15. The device of claim 11 including an evacuation chamber formed by a housing and being adapted to receive a container, a shaft extending through said housing to removably mount said filter capping head for reciprocation therein, a tubular cartridge type container gripper housing removably received in said housing in coaxial alignment with said filter capping head and means in said container gripper housing responsive to evacuation of said chamber for holding said container during evacuation and capping thereof,

16. The device of claim 15 wherein stop means is mounted in said housing for engagementwith said upper ring on said filter and capping head to move said trigger assembly relative thereto whereby said clamping member clamping 'lug portions are moved out of engagement with said container cap gripping ring.

17. The device of claim 11 wherein said means interconnecting said filter mounting head and said clamping members comprises a groove in said clamping members aligned with a groove in said filter mounting head, and a clamping spring received in said aligned groove for resiliently joining said clamping members to said filter mounting head allowing relative movement there-between in a generally radial direction as said trigger assembly is shifted relative to the filter mounting head.

18. In a vacuum capping machine wherein containers filled with particulate material are subjected to evacuation and subsequent capping, a housing having a container receiving bore therein, means removably mounted in said bore in sealed relation therewith for gripping a peripheral portion of a container received therein for evacuation and capping, a filter and cap applicator unit mounted for sealed reciprocation and rotation in said housing, said filter and cap applicator unit including connected upper and lower mounting rings forming a trigger assembly having a cylindrical bore, a filter mounting head mounted within said cylindrical bore, said trigger assembly being shiftable with respect to said filter mounting head, said lower mounting ring having a container cover gripping ring thereon, a clamping member pivotably connected to said trigger assembly and means interconnecting said filter mounting head and said clamping member, said clamping member having a clamping lug portion thereof which is movable into constricting engagement with a eripheral portion of said container cover gripper ring to effect a force controlled grip on said container cover for application to said container held by said means gripping a peripheral portion thereof.

References Cited by the Examiner UNITED STATES PATENTS 2,120,272 6/1938 Williams et al 53-95 X 2,670,117 2/1954 K-antor 5395 X 3,191,354 6/1965 M CElIOY 61; 3 1. 53-112 X TRAVIS S. MCGEHEE, Primary Examiner. 

1. IN A VACUUM CAPPING MACHINE WHEREIN CONTAINERS FILLED WITH PARTICULATE MATERIAL ARE SUBJECTED TO EVACUATION AND SUBSEQUENT CAPPING, THE PROVISION OF A COMBINATION FILTER AND CAP APPLICATION UNIT ADAPTED TO COVER A CONTAINER DURING EVACUATION THEREOF TO PREVENT DISPLACEMENT OF SAID MATERIAL THEREFROM AND THEREAFTER APPLY A CAP TO SAID CONTAINER TO SEAL THE SAME, SAID FILTER AND CAP APPLICATION UNIT COMPRISING AN INVERTED CUP-LIKE FILTER MEMBER PRESENTING AN UNINTERRUPTED POROUS FILTERING AREA THROUGHOUT, FILTER MOUNTING MEANS SUPPORTING SAID FILTER MEMBER IN UNOBSTRUCTING RELATION THROUGHOUT AT LEAST SUBSTANTIALLY THE ENTIRE FILTERING AREA THEREOF, CAP GRIPPING MEANS AT LEAST PARTIALLY CARRIED BY SAID FILTER MOUNTING MEANS AND ASSOCIATED WITH THE BOTTOM MARGINAL AREA OF SAID FILTER MEMBER TO ENGAGE A CAP ACROSS A MOUTH PORTION OF SAID FILTER MEMBER, AND MEANS MOUNTING SAID FILTER AND CAP APPLICATION UNIT FOR RECIPROCATION INTO AND OUT OF ASSOCIATION WITH A CONTAINER FOR CONTAINER EVACUATION AND CAP TRANSFER. 